Definition
A stall of the horizontal tailplane (the small wing at the rear of the aircraft) caused by ice accumulation on its leading edge. The tailplane normally produces a downward force to keep the nose up; when contaminated with ice, it can stall at airspeeds and angles of attack well below those of the main wing, causing a sudden and often violent nose-down pitch, especially when flaps are extended.
Plain English
When ice builds up on the small wing at the back of the aircraft, that small wing can stop working properly. Because it normally holds the nose up, when it stops working the nose drops sharply on its own — often without warning, and often when the pilot lowers the flaps.
Context Anchor
Seen in icing discussions, approach and landing planning, flap use, and abnormal nose-down pitch behavior in instrument conditions.
Derivation
From 'tailplane' (the horizontal stabilizer at the tail) and 'stall' (loss of lift due to airflow separation). 'Contaminated' here means 'with ice on it' — the surface is no longer clean. Naming it this way emphasizes that the cause is ice on the tail, not on the main wings.
Why Pilots Care
It can cause an abrupt and uncommanded loss of pitch control, especially during approach or descent in icing conditions.
Grounding Statement
Picture ice roughening the small horizontal surface at the tail until the air no longer flows smoothly over it.
Intuition Check
Do not read stall here as an engine stopping, and do not assume it means the main wing has stalled. In ICTS, the tail surface is the part losing smooth airflow because ice has changed its shape.
Example Sentence 1
After picking up ice on the descent, the crew delayed extending full flaps because of the risk of an ICTS.
Example Sentence 2
During an instrument approach in visible moisture, the crew stayed alert for ICTS by monitoring pitch attitude closely.